cli: Make --xml option parsing less special

We can make `--xml` fit the common xml cli option paradigm, which
less us drop a whole bunch of special handling in virt-xml

Signed-off-by: Cole Robinson <crobinso@redhat.com>

tests/test_cli.py

@@ -1413,7 +1413,7 @@ c.add_invalid("test-for-virtxml --remove-device --host-device 1 --update --confi
 c.add_invalid("test-for-virtxml --edit --graphics password=foo,keymap= --update --confirm", input_text="yes", grep="(not supported by the connection driver: virDomainUpdateDeviceFlags|persistent update of device 'graphics' is not supported)")
 c.add_invalid("--build-xml --memory 10,maxmemory=20", grep="--build-xml not supported for --memory")
 c.add_invalid("test-state-shutoff --edit sparse=no --disk path=blah", grep="Don't know how to match device type 'disk' property 'sparse'")
-c.add_invalid("test --add-device --xml ./@foo=bar", grep="--xml can only be used with --edit")
+c.add_invalid("test --add-device --xml ./@foo=bar", grep="Cannot use --add-device with --xml")
 c.add_invalid("test-for-virtxml --edit --boot refresh-machine-type=yes", grep="Don't know how to refresh")
 c.add_compare("test --print-xml --edit --vcpus 7", "print-xml")  # test --print-xml
 c.add_compare("--edit --cpu host-passthrough", "stdin-edit", input_file=(_VIRTXMLDIR + "virtxml-stdin-edit.xml"))  # stdin test

virtinst/cli.py

@@ -493,7 +493,7 @@ def fail_conflicting(option1, option2):
 
 def _get_completer_parsers():
     return VIRT_PARSERS + [ParserCheck, ParserLocation,
-            ParserUnattended, ParserInstall, ParserCloudInit, ParserXML,
+            ParserUnattended, ParserInstall, ParserCloudInit,
             ParserOSVariant]
 
 
@@ -947,6 +947,7 @@ def add_os_variant_option(parser, virtinstall):
 
 
 def add_xml_option(grp):
+    ParserXML.register()
     grp.add_argument("--xml", action="append", default=[],
             help=_("Perform raw XML XPath options on the final XML. Example:\n"
                    "--xml ./cpu/@mode=host-passthrough\n"
@@ -1608,23 +1609,21 @@ class ParserXML(VirtCLIParser):
         cls.add_arg("xpath.create", "xpath_create", can_comma=True)
         cls.add_arg("xpath.value", "xpath_value", can_comma=True)
 
-    def _parse(self, inst):
+    def parse(self, inst):
+        """
+        Parse --xml option string into XMLManualAction instances and append
+        to guest.xml_actions.
+        """
+        inst = self.guest.xml_actions.new()
+
+        # Default `--xml FOO` to `--xml xpath.set=FOO`
         if not self.optstr.startswith("xpath."):
             self.optdict.clear()
             self.optdict["xpath.set"] = self.optstr
 
-        super()._parse(inst)
+        super().parse(inst)
 
-
-def parse_xmlcli(guest, parservalue):
-    """
-    Parse --xml option string into XMLManualAction instances and append
-    to guest.xml_actions.
-    """
-    for optstr in parservalue:
-        inst = guest.xml_actions.new()
-        ParserXML(optstr).parse(inst)
-        guest.xml_actions.append(inst)
+        self.guest.xml_actions.append(inst)
 
 
 def _add_xpath_args(cls):

virtinst/virtinstall.py

@@ -664,7 +664,6 @@ def build_guest_instance(conn, options):
         # default disk paths are generated based on VM name
         set_cli_default_name(guest)
         cli.run_all_parsers(options, guest)
-        cli.parse_xmlcli(guest, options.xml)
         set_cli_defaults(options, guest)
 
     installer.set_install_defaults(guest)

virtinst/virtxml.py

@@ -109,9 +109,6 @@ def validate_action(action, conn, options):
         fail(_("--build-xml not supported for --%s") %
              action.parserclass.cli_arg_name)
 
-    if action.parserclass is cli.ParserXML and not action.is_edit:
-        fail(_("--xml can only be used with --edit"))
-
     stub_guest = Guest(conn)
     if not action.parserclass.prop_is_list(stub_guest):
         if action.is_remove_device:
@@ -148,7 +145,7 @@ def check_action_collision(options):
 
 def check_xmlopt_collision(options):
     collisions = []
-    for parserclass in cli.VIRT_PARSERS + [cli.ParserXML]:
+    for parserclass in cli.VIRT_PARSERS:
         value = getattr(options, parserclass.cli_arg_name)
         if value:
             collisions.append((parserclass, value))
@@ -236,10 +233,6 @@ def action_edit(action, guest):
     parservalue = action.parservalue
     selector = action.selector
 
-    if parserclass is cli.ParserXML:
-        cli.parse_xmlcli(guest, parservalue)
-        return []
-
     if parserclass.guest_propname:
         inst = _find_objects_to_edit(guest, "edit",
                                      selector, parserclass)